9QSY
Cryo-EM structure of aquaporin 3 at pH 5.5
Summary for 9QSY
| Entry DOI | 10.2210/pdb9qsy/pdb |
| EMDB information | 53344 |
| Descriptor | Aquaporin-3 (2 entities in total) |
| Functional Keywords | membrane protein, glycerol channel, hydrogen peroxide transport, tetramer |
| Biological source | Homo sapiens (human) |
| Total number of polymer chains | 4 |
| Total formula weight | 129586.20 |
| Authors | Huang, P.,Venskutonyte, R.,Lindkvist-Petersson, K. (deposition date: 2025-04-07, release date: 2026-02-18) |
| Primary citation | Huang, P.,Venskutonyte, R.,Wilson, C.J.,Bsharat, S.,Prasad, R.B.,Gourdon, P.,Artner, I.,de Groot, B.L.,Lindkvist-Petersson, K. Structural insights into AQP3 channel closure upon pH and redox changes reveal an autoregulatory molecular mechanism. Nat Commun, 16:10997-10997, 2025 Cited by PubMed Abstract: Regulation of intracellular levels of reactive oxygen species (ROS) remains poorly understood. Aquaporin 3 (AQP3) facilitates the membrane transport of hydrogen peroxide (HO), a key ROS signaling molecule. Here we elucidate the molecular mechanism of AQP3 and show that its regulatory properties are both pH dependent and autoregulated by HO. Using single particle cryo-electron microscopy, we present open and closed conformations of human AQP3. At pH 8.0, the channel adopts an open state, while acidic pH or exposure to HO promotes closure via a large conformational rearrangement of extracellular loop E. These findings reveal a mechanism for autoregulation of HO transport and establish AQP3 as a key modulator of redox homeostasis in human pancreatic β-cells. PubMed: 41429774DOI: 10.1038/s41467-025-67144-2 PDB entries with the same primary citation |
| Experimental method | ELECTRON MICROSCOPY (3.2 Å) |
Structure validation
Download full validation report






